Mercury 25 HP..mystery #...impeller no good?

[bu11yz]

I've got a 25 hp Mercury..Ser.# 0G003213...not sure of the year...been tryng to hunt down the year with the serial #..think its a 93 Sea Pro or Marathon.I just started it today and had no water running out of the top "pee" hole.It did seem to be running out about halfway up the motor...Is my pump/impeller shot or is something blocking the waterflow? Can I drop the lower unit or do I have to relplace gaskets if I do this? I don't have a manual other than the owners manual which tells basically nothing....

 

[roachblade]

Re: Mercury 25 HP..mystery #...impeller no good?

Hi I have a similar outboard, dropped the gearbox out today to check impellor, there is no gaskets between the stalk and the gearbox/prop housing.
(you do have to remove startor and disconnect the top link of the gear selector first). Mine also will not put water out of anywhere except just a bit out of the prop. I beleive that there is a thermostat under where the top hose comes off the motor, but I have not found out how it works yet.

 

[Fun Times]

Re: Mercury 25 HP..mystery #...impeller no good?

I've got a 25 hp Mercury..Ser.# 0G003213...not sure of the year...been tryng to hunt down the year with the serial #..think its a 93 Sea Pro or Marathon.I just started it today and had no water running out of the top "pee" hole.It did seem to be running out about halfway up the motor...Is my pump/impeller shot or is something blocking the waterflow? Can I drop the lower unit or do I have to relplace gaskets if I do this? I don't have a manual other than the owners manual which tells basically nothing....

For looking up parts your engine is considered a 1994, Engine serial number: 0G003213 Model number 1025211PD.
1994 MERCURY 25 MLH
Engine manufacture Date was on: 07/13/1993.

The service manual part number from mercury marine is (90-435093) That covers /18/20/25 hp's.

It's always best to start with a new impeller when testing for low water pressure then go from there.

 

[CharlieB]

Re: Mercury 25 HP..mystery #...impeller no good?

Look up parts views and #'s here, have that serial # handy

http://www.mercruiserparts.com/selectModels3.asp?type_id=MAR

Once you have the OEM part # you can search anywhere for the correct part.

 

[bu11yz]

Re: Mercury 25 HP..mystery #...impeller no good?

Thanks for the info..I'm gonna pull it apart today and see if I can figure out whats going on.Its kinda tough without a manual....I'm hoping theres just some crap in there but as usual I'm preparing for the worst....

 

[bu11yz]

Re: Mercury 25 HP..mystery #...impeller no good?

I pulled it apart, the impeller looks worn...not sure when it was changed last.My new problem looks to be the upper roller bearing is very corroded..is this easy to change or do I need to have it done at the dealer?Does it require a puller?The gearbox housing for my motor is no longer available so i don't want to start hammering and risk damaging it.The bearing is only 15 bucks so i might as well replace it while I have it apart.Am I better off replacing the whole water pump as a assembly or just the impeller and the gasket?